i cant beleive some people, their check light comes on and they are just like oh well its probably nothing i will just drive with it on... even if it is nothing (by nothing i mean a sensor went out and threw the code) you still find out its the sensor and fix it... you dont want your check engine light on when something really does happen and you wont know about it...
Putting things off makes it more expensive in the end....
As for the low alternator speed.. you can get it bench tested for free and they will tell you.. but unless your lights are dimming while you drive, or while you roll up your windows you are fine.. theres no pointi n taking your alternator in and out if you KNOW its not that. My abs light along with afew others came on both times my alternator went out also.
David